Abstract:

A feeding device configured for insertion into the gastrointestinal tract
of a patient, and dynamic movement through the gastrointestinal tract
toward the jejunum. The device includes an elongate tubular member having
a plurality of distal projections disposed on an exterior surface
thereof. The projections extend radially outwardly from the exterior
surface of the tubular member a distance sufficient to engage an interior
surface of the gastrointestinal tract during peristaltic contractions
therein, and are configured to promote ingress of the device in response
to the contractions. At least some of the projections are soluble under
bodily conditions at the gastrointestinal tract, thereby facilitating
removal of the feeding device.

Claims:

1. A medical device configured for dynamic movement through a body canal
toward an interior target site and removal therefrom, said device
comprising an elongate tubular member having a plurality of distal
projections disposed on an exterior surface thereof, said projections
extending outwardly from the exterior surface of the tubular member a
distance sufficient to engage an interior surface of the body canal
during bodily contractions therein, said distal projections being
configured so as to promote ingress of said device in response to said
contractions, at least some of said projections being formed of a
composition that is soluble under bodily conditions at said body canal.

2. The device of claim 1, wherein said distal projections comprise a
series of flaps along said external surface.

3. The device of claim 2, wherein said series of flaps comprises a
plurality of distal flaps arranged near a distal tip of said tubular
member, and a series of secondary flaps arranged proximal to said distal
flaps, said secondary flaps having a configuration different than said
distal flaps.

4. The device of claim 3, wherein said distal flaps and said secondary
flaps comprise tips that are oriented in opposite directions.

5. The medical device of claim 1, further comprising a series of apertures
along the surface of said tubular member.

7. The medical device of claim 1, wherein the distal projections are
adhered to the surface of the tubular member.

8. The medical device of claim 1, wherein the distal projections are
molded to the surface of the tubular member.

9. The medical device of claim 1, wherein the exterior surface of said
tubular member includes a plurality of grooves, and wherein said distal
projections extend radially outwardly from said grooves.

10. The medical device of claim 1, wherein said tubular member comprises
PVC, polyurethane or silicone.

11. A naso-jejunal feeding device for insertion into a patient, said
feeding device configured for dynamic movement into and through the
patient's gastrointestinal tract toward an internal target site at the
jejunum of the patient, the feeding device comprising: a hollow tubular
member having a distal portion and an outer surface; a plurality of flaps
disposed on said outer surface at said distal portion, said flaps
projecting outwardly from the surface of the tubular member so as to
engage an interior surface of the gastrointestinal tract and configured
so as to promote ingress of the feeding tube toward said jejunum in
response to peristaltic contractions; said flaps being formed of a
material that dissolves when said tubular member is received in the
gastrointestinal tract, said tubular member further comprising a
plurality of apertures sized and shaped to permit fluid-like materials to
enter the jejunum from an interior space of said tubular member.

13. The naso-jejunal feeding device of claim 11, wherein said flaps
comprise respective first and second sets of flaps disposed along said
outer surface, said flaps of said first set having a shape, size and
orientation that is different from said flaps of said second set, each of
said flaps being configured to promote said ingress in response to
peristaltic contractions.

14. The naso-jejunal feeding device of claim 13, wherein said first set of
flaps comprise tips that are oriented in a different direction than tips
of said second set of flaps.

15. A medical device configured for dynamic movement through a body canal
toward an interior target site and removal therefrom, said device
comprising an elongate tubular member having a plurality of distal
projections disposed on an exterior surface thereof, said projections
extending radially outwardly from the exterior surface of the tubular
member a distance sufficient to engage an interior surface of the body
canal during bodily contractions therein, said distal projections being
configured so as to promote ingress of said device in response to said
contractions, at least some of said projections being removable from said
elongate tubular member under bodily conditions at said body canal for
facilitating removal of said feeding device from said target site.

16. The medical device of claim 15, wherein said projections are soluble
under said conditions at said body canal.

17. The medical device of claim 15, further comprising an adhesive for
adhering said at least some distal projections to said tubular member
exterior surface, said adhesive being soluble under said conditions at
said body canal, such that said adhered projections are removable from
said device upon dissolution of said adhesive.

18. The medical device of claim 15, wherein the exterior surface of said
tubular member includes a plurality of grooves, and wherein distal
projections extend radially outwardly from said grooves.

[0003]The present invention relates to a device for invading body canals
non-destructively and with a minimum of trauma. More particularly, the
invention relates to a device, such as a feeding tube, having one or more
removable external projections for dynamic advancement of the distal end
of the device to the desired body site.

[0004]2. Background Information

[0005]Medical devices intended for non-destructive invasion of body canals
have typically been provided with a low friction external surface. The
low friction surface has a slippery texture to facilitate ingress of the
device into the body canal for carrying out a medical procedure, and
egress of the device from the body canal following termination of the
procedure. Once inserted, such low friction devices were generally
suitable for their intended use. However, the devices were often
difficult to deliver and properly position at the desired site. In
addition, insertion required a good deal of physician time and effort to
insure adequate placement.

[0006]Recently, as set forth in U.S. Pat. Nos. 6,589,213 and 6,767,339,
incorporated by reference herein, it was found that the ingress of the
medical device or other instrumentation into a desired body site could be
facilitated by providing a structure on the external surface of the
device having a bi-directional coefficient of friction with respect to
the tissue within the body cavity or canal that is engaged by the device
during ingress. As disclosed in the incorporated-by-reference patents,
the surface structure could be positioned along the device in a manner
such that naturally occurring dynamic functions of the body, such as
peristaltic contractions, could be used to grasp the surface structure of
the device upon insertion, and carry the device toward the desired work
site.

[0007]Devices such as those disclosed in the incorporated-by-reference
patents have been successfully used, among others, as tubes for
delivering feeding materials, drugs, contrast materials or saline, to a
target site, within the body of the patient. One primary use of such
devices is as jejunal feeding tubes ("J-tubes") for delivering
nutritional products through the esophagus, and thereafter through the
stomach or small intestine for delivery to the jejunum. Unlike
conventional gastrostomy tubes ("G-tubes") that are utilized for delivery
of nutritional products into the stomach, J-tubes bypass the stomach, and
deposit the nutritional products directly into the jejunum (the middle
section of the small intestine). Delivery of nutritional products to the
jejunum is often preferred to delivery into the stomach, as it decreases
the risk of adverse conditions such as gastric reflux and aspiration. In
addition, in many cases, delivery directly into the jejunum provides
better success in reaching patient nutritional targets, and does so at a
more rapid rate than may be achieved with a conventional G-tube.

[0008]The device disclosed in the '339 patent employed a series of
cilia-like flaps positioned along the external surface of the device. The
flaps were positioned in a manner such that the surface could be grasped
by the peristaltic contractions, and the distal end of the device
propelled toward the target site. Self-advancing tubes, such as those
described in the '339 patent, are available commercially from Cook
Incorporated, of Bloomington, Ind., and are sold under the trademark
TIGER TUBE®. Such tubes have been well received in the medical
community, and have been found to achieve a high success rate in post
pyloric placement of the feeding tube.

[0009]Once successful placement is attained with the self-advancing tubes,
there is little or no benefit to maintaining the surface structure, such
as the flaps of the '339 patent, on the exterior of the tube. Although
the flaps are generally flexible, the presence of such flaps is
unnecessary when the tube is withdrawn, and the additional diameter
occupied by the flaps may impose an impediment to withdrawal. It would be
desirable to provide a device having surface structure suitable for
enhancing advancement to the target site by peristaltic contraction, and
in which the surface structure is removable following successful
placement of the device.

BRIEF SUMMARY

[0010]The present invention addresses the shortcomings of the prior art.
In one form thereof, the invention comprises a medical device configured
for dynamic movement through a body canal toward an interior target site
and removal therefrom. The device includes an elongate tubular member
having a plurality of distal projections disposed on an exterior surface
thereof. The projections extend outwardly from the exterior surface of
the tubular member a distance sufficient to engage an interior surface of
the body canal during bodily contractions therein. The distal projections
are configured to promote ingress of the device in response to the
contractions. At least some of the projections are formed of a
composition that is soluble under bodily conditions encountered at the
body canal.

[0011]In another form thereof, the invention comprises a naso-jejunal
feeding device for insertion into a patient. The feeding device is
configured for dynamic movement into and through the patient's
gastrointestinal tract toward an internal target site at the jejunum of
the patient. The feeding device includes a hollow tubular member having a
distal portion and an outer surface, wherein a plurality of flaps is
disposed on the outer surface at the distal portion. The flaps project
outwardly from the surface of the tubular member so as to engage an
interior surface of the gastrointestinal tract, and are configured so as
to promote ingress of the feeding tube toward the jejunum in response to
peristaltic contractions. The flaps are formed of a material that
dissolves when the tubular member is received in the gastrointestinal
tract. The tubular member further includes a plurality of apertures sized
and shaped to permit fluid-like materials to enter the jejunum from the
interior of the tubular member.

[0012]In still another form thereof, the invention comprises a medical
device configured for dynamic movement through a body canal toward an
interior target site and removal therefrom. The device includes an
elongate tubular member having a plurality of distal projections disposed
on an exterior surface thereof. The projections extend radially outwardly
from the exterior surface of the tubular member a distance sufficient to
engage an interior surface of the body canal during bodily contractions
therein. The distal projections are configured so as to promote ingress
of the device in response to the contractions. At least some of the
projections are removable from the elongate tubular member under bodily
conditions at the body canal for facilitating removal of the feeding
device from the target site.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a side view of the distal portion of a device according to
an embodiment of the present invention;

[0014]FIG. 2 is a side view of the device of FIG. 1, following dissolution
of the side flaps;

[0015]FIG. 3 is a side view of the distal portion of an alternative
embodiment of a device according to the present invention; and

[0016]FIG. 4 is a longitudinal sectional view of the device of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017]For purposes of promoting an understanding of the present invention,
reference will now be made to the embodiments illustrated in the
drawings, and specific language will be used to describe the same. It
should nevertheless be understood that no limitation of the scope of the
invention is thereby intended, such alterations and further modifications
in the illustrated device, and such further applications of the
principles of the invention as illustrated therein being contemplated as
would normally occur to one skilled in the art to which the invention
relates.

[0018]In the following discussion, the terms "proximal" and "distal" will
be used to describe the opposing axial ends of the inventive device, as
well as the axial ends of various component features of the device. The
term "proximal" is used in its conventional sense to refer to the end of
the device (or component thereof) that is closest to the operator during
use of the device. The term "distal" is used in its conventional sense to
refer to the end of the device (or component thereof) that is initially
inserted into the patient, or that is closest to the patient during use.

[0019]FIG. 1 illustrates a side view of the distal portion of a device 10,
according to an embodiment of the present invention. In this embodiment,
device 10 is fashioned as a feeding tube, such as a naso-jejunal tube,
for delivering nutritional products directly into the jejunum of a
patient. Those skilled in the art will appreciate that the described use
of device 10 herein as a feeding tube is exemplary only, and that
additional uses may be made for device 10. For example, in addition to
nutritional products, device 10 may be used for delivering other
fluid-like materials such as drugs, contrast materials or saline to
target sites in the patient. Device 10 may also be used as a feeding tube
for other than naso-jejunal feeding, and/or may be used for delivery of
specified materials to target sites in other body canals. All such uses
are considered within the scope of the invention.

[0020]Only the distal portion of device (feeding tube) 10 is depicted in
the figures. The proximal portions of such devices are conventional, and
further description of the proximal portion is not necessary for an
understanding of the features of the present invention. In a preferred
embodiment, an 8 to 16 French tube is utilized, having a minimum overall
length of about 154 cm. Those skilled in the art will appreciate that
these dimensions, as well as other dimensions recited herein, are
exemplary only, and that other dimensions may be appropriate for a
particular case. Typically, such tubes are formed of a flexible polymeric
composition, such as PVC or polyurethane. Other flexible elastomeric
compositions, such as silicone, may alternatively be utilized in a
particular case.

[0021]In the non-limiting embodiment shown, device 10 is fashioned
generally similar to the feeding tube described in the incorporated by
reference '339 patent. Device 10 comprises an elongated tubular member 12
having a plurality of projections extending radially from the external
surface of the tubular member. In the embodiment of FIG. 1, the
projections comprise a series of generally cilia-like flaps 16, 26
adhered to the outer surface 14 of the tubular member. A plurality (such
as four) of distal flaps 16 are disposed about the perimeter of the
distal end portion of outer surface 14 at approximately equal intervals
(i.e., at 90° intervals), and are positioned near the distal tip
20 of tubular member 12. In the embodiment shown, the distal flaps 16
comprise a first oppositely disposed pair of distal flaps 17 located,
e.g., about 0.7 cm from the distal tip 20 of device 10, and a second
oppositely disposed pair of distal flaps 18 located, e.g., about 1.0 cm
from the distal tip 20 of device 10, as measured from the base 19 of each
of the flaps 17, 18. When straightened, each of the distal flaps is
approximately 1 cm in length.

[0022]Flaps 16 are configured to cause device 10 to be propelled forwardly
by naturally occurring contractions of the tissue of the body canal, and
to resist egress of the device. In particular, when the device 10 is
being inserted into the body canal, the distal flaps 16 provide a
relatively large diameter near the closed distal tip 20 of the device
that can be readily grasped by the tissue of the body canal during
peristaltic contractions.

[0023]A plurality of secondary flaps 26 is disposed along the outer
surface 14 of tubular member 12 proximal of the distal tip 20 and the
distal flaps 16. The secondary flaps 26 preferably alternate along
opposite sides of the device at approximately 2 cm intervals. Thus, the
secondary flaps 26 comprise a first series of secondary flaps 28 disposed
along the top side of the device (as viewed in FIG. 1) and spaced at
approximately 4 cm intervals, and a second series of secondary flaps 29
disposed along the bottom side of the device (as viewed in FIG. 1) and
spaced at approximately 4 cm intervals.

[0024]In the preferred embodiment, each of the secondary flaps 26 measures
approximately 0.5 cm in length when straightened. Each of the secondary
flaps 26 preferably has a truncate shape comprising a base 27 measuring
approximately 0.016 cm in width, and a tip 30 measuring approximately
0.010 cm in width. Preferably, each of the secondary flaps 26 is
moderately curved outwardly so as to prevent the secondary flaps 26 from
adhering to the outer surface 14 of tubular member 12, and to allow the
tip 30 to engage the tissue of the body canal (not shown). The secondary
flaps 26 are also preferably configured to orient the secondary flap tips
30 rearwardly (i.e., away from the distal tip 20 of the device 10). This
rearward orientation of the secondary flaps 26 causes device 10 to be
propelled forwardly by the naturally occurring peristaltic contractions
of the tissue of the body canal during the insertion process, and also
resists egress of the device. The secondary flaps 26 are also
sufficiently flexible to prevent trauma to the tissue of the body canal
during insertion of device 10.

[0025]Preferably, flaps 16, 26 are distributed along the distal 50 cm of
device 10. In the embodiment shown, device 10 further comprises a
plurality of apertures 40 also disposed along the distal portion of
elongated tubular member 12. Apertures 40 preferably measure about 0.5 cm
in diameter, and provide openings through which feeding material or other
fluids can exit the interior of the device and enter the body canal or
cavity. In the embodiment shown, the apertures 40 are alternately
disposed along opposite sides of the device, and are preferably located
along the sides of the device that are 90° offset from the sides
of the device along which the secondary flaps 26 are located (i.e., along
the front and back sides of the device as viewed in FIG. 1).

[0026]Providing a device, such as a feeding tube, with a plurality of
flaps enhances the dynamic movement of the device within the body canal.
The flaps are positioned along the surface of the device in a manner such
that the naturally occurring peristaltic contractions grasp the flaps
upon insertion, and carry the distal end of the device into the jejunum.
As such, the flaps provide a very convenient manner of inserting the
device, and directing its distal tip to the target site, by utilizing
natural body contractile functions.

[0027]It is, of course, apparent that at some point the device will have
to be removed from the body canal. Typically, removal will occur upon
completion of the medical procedure for which the device has been
inserted, such as enteral feeding. Although the flaps 16, 26 are
beneficial for propelling the device forward during peristaltic
contractions as described, they do not contribute to the removal of the
device following termination of the procedure. During removal ("egress"),
the device is withdrawn in a direction opposite to that urged by the
peristaltic contractions. In this case, any grasping or contractile
effect is counterproductive to smooth removal of the device. In addition,
the additional diameter occasioned by the presence of the flaps may
impose an impediment to withdrawal.

[0028]In a preferred embodiment of the present invention, flaps 16, 26 are
formed of a composition that is soluble under the conditions to which the
device is exposed in the body canal. Thus, for example, when device 10 is
a naso-jejunal feeding tube, flaps 16, 26 are formed of a composition
that is soluble under conditions encountered in the lower part of the
digestive tract (i.e., the gut). As a result, at some point following
insertion of the device, flaps 16, 26 dissolve and are no longer present
along the outer surface of device 10. This eliminates a potential
impediment to removal of the device during egress, and facilitates smooth
withdrawal. FIG. 2 illustrates the profile of device 10 following
dissolution of the flaps (the original positioning of flaps 16, 26 is
shown in phantom).

[0029]Although in the preferred embodiment described herein, all of flaps
16, 26 are formed of a soluble composition as described, this need not be
the case in each and every instance. Rather, if desired, in some
instances one or more flaps need not necessarily be formed of the soluble
composition. However, it is believed that the benefits of the invention
are best achieved when most, if not all, of flaps 16, 26 are soluble or
otherwise capable of removal as described herein.

[0030]In order to enhance dissolution, flaps 16, 26 may be formed of a
biosoluble plastic. Non-limiting examples of plastics suitable for a
particular use include poly(dl-lactide) (DLPLA); poly(l-lactide) (LPLA);
polyglycolide (PGA); poly(dioxanone) (PDO);
poly(glycolide-co-trimethylene carbonate) (PGA-TMC);
poly(l-lactide-co-glycolide) (PGA-LPLA); poly(dl-lactide-co-glycolide)
(PGA-DLPLA); poly(l-lactide-co-dl-lactide) (LPLA-DLPLA); and
poly(glycolide-co-trimethylene carbonate-co-dioxanone) (PDO-PGA-TMC).
This listing of suitable biosoluble compositions is not intended to be
complete, and those skilled in the art will appreciate that other
biosoluble compositions may be substituted for the compositions listed
above, depending upon the intended use of device 10 and the body canal in
which it is inserted.

[0031]Flaps 16, 26 may be attached to device 10 by any suitable means
depending upon the compositions of device 10 and the flaps. Thus, for
example, flaps 16, 26 may be adhered to the external surface of tubular
member 12 using an appropriate biocompatible adhesive. As another
example, flaps 16, 26 can be molded onto the surface of the tubular
member. Those skilled in the art will appreciate that other suitable
mechanisms for attaching structures may be substituted, depending upon
the compatibility of the tubular member and the flaps.

[0032]In the preferred embodiment described and illustrated above, the
projections extending from the external surface of tubular member 12
comprise a series of flaps 16, 26 distributed along the distal length of
device 10. As stated, in the non-limiting embodiment shown, flaps 16, 26
are distributed essentially in the same general manner as the flaps in
the incorporated-by-reference '339 patent. This arrangement has been
found to be very effective in promoting contractions, such as
peristalsis, in commercially available tubes, such as the aforementioned
TIGER TUBE®. However, the flaps in the incorporated-by-reference
patent are not indicated as being dissolvable or otherwise removable for
enhancing withdrawal of the device.

[0033]Those skilled in the art will appreciate that the arrangement of the
projections, such as flaps 16, 26 described hereinabove, along the
external surface of the elongated tubular member is merely one example of
suitable projections. Numerous alternative arrangements may also be
effective for the described purposes, all such arrangements being
considered within the scope of the invention. For example, it is not
necessary to have two distinct sets of flaps 16, 26 with different
configurations. Rather, all flaps can have the same configuration, which
need not necessarily be either of the configurations described herein.
Similarly, it is not necessary for flaps 16, 26 to be distributed along
the surface of the distal end of device 10 in the configuration
described. Rather, in some cases, random, spiral, etc. configurations
will be satisfactory. Since the purpose of the radial projections (e.g.,
flaps) is to provide a grasping surface for the bodily contractions, a
virtually unlimited number of arrangements could be fashioned to
facilitate insertion of the device via such contractions, the examples
provided herein merely representing one suggested arrangement for a
particular use.

[0034]Although the examples provided hereinabove describe the external
projections as a series of flaps, those skilled in the art will
appreciate that other structures may also be fashioned to enhance dynamic
advancement of the device by bodily contractions, and are also within the
scope of the invention. FIG. 3 illustrates a device 50 comprising an
elongated tubular member 52 and a series of mounds 54 positioned along
the external surface of tubular member 52. In the embodiment of FIG. 3,
mounds 54 can comprise a series of distal mounds 56 and secondary mounds
58, positioned as in the previous embodiment with the flaps. Mounds 54
can be formed of the compositions described above for flaps 16, 26, or
any other compositions that are suitable for attachment to tubular member
52, and that are capable of dissolving under the conditions in the body
canal in which device 50 is inserted. Device 50 may also include
apertures 60 for transmission of fluid products from the inside of
tubular member 52 to the environment exterior of device 50.

[0035]Mounds 54 may alternatively be positioned along the external surface
of tubular member 52 in any other configuration, such as a spiral or a
random configuration, suitable for insertion of device 50 by bodily
contractions as described. Mounds 54 may be adhered or otherwise attached
to the outer surface of tubular member 52, or can be formed to project
outwardly (radially) from respective grooves 53 (FIG. 4) formed in the
outer surface of tubular member 52.

[0036]In addition to the specific external projections described and
illustrated herein (flaps and mounds), those skilled in the art will
appreciate that the projections may alternatively comprise any other
size, shape and orientation suitable for the intended purpose. Thus, for
example, the projections can comprise a series of bumps, ribs or ridges
along the outer surface of the tubular portion of the inventive device.
The projections likewise need not all be of the same type. Thus, for
example, the projections may comprise combinations of flaps, mounds,
bumps, etc., distributed along the external surface of the tubular member
in a manner to promote ingress resulting from bodily contractions. The
skilled artisan can readily determine an optimal configuration and
arrangement of projections from the surface of the device for a
particular intended use when following the teachings of this invention.

[0037]Those skilled in the art will appreciate that the external
projections need not necessarily be formed of a composition that is
soluble under the conditions encountered within the body canal. Although
removing the projections by dissolution in the canal represents one
preferred embodiment, other methods of removing the projections are also
possible, and are considered within the scope of the invention. For
example, the projections may be engaged with the outer surface of the
tubular member in a manner such that they are capable of disengagement
therefrom by the time that the device is to be withdrawn. As one example,
the projections can be formed of a nonsoluble composition, e.g., of the
same or a similar composition as that of the tubular member. These
projections can then be adhered (e.g., by a soluble adhesive such as
cyanoacrylate) or otherwise engaged (e.g., by dissolvable sutures) to the
outer surface of the tubular member. In this instance the adhesive or
other dissolvable structure dissolves prior to withdrawal of the device.
For applications such as in the gastrointestinal tract, these nonsoluble
external projections will simply pass as free floating structures through
the gastrointestinal tract after disengaging from the tubular structure.
If the device is to be used in body canals other than the
gastrointestinal tract, the medical professional must, of course,
consider the feasibility of allowing a free floating projection member to
pass through the particular canal.

[0038]When selecting a particular composition for the dissolvable
projection, adhesive, etc., for use in the invention, one should consider
the length of time that is typically required for the device to be fully
passed through the body canal by the contractions to the intended target
site. Thus, for example, when a feeding device is configured for dynamic
movement through the patient's gastrointestinal tract by peristaltic
contraction, it is known that the device will often take between 5 and 15
hours for movement through the GI tract and proper seating of the distal
end of the device in the jejunum. As a rough rule of thumb, such devices
may advance about 10 cm per hour through the tract. The feeding device
may be left in place as long as necessary for providing nutrition to the
patient, with such indwelling time usually not exceeding about sixty
days. The dissolvable projection and/or adhesive should be selected such
that it does not dissolve in a shorter time period than that required for
proper seating of the device in the canal, but wherein it is at least
partially, if not fully, dissolved prior to withdrawal of the device.

[0039]While these features have been disclosed in connection with the
illustrated preferred embodiments, other embodiments of the invention
will be apparent to those skilled in the art that come within the spirit
of the invention as defined in the following claims.